WT.tv
WT.tv=major.minor.revision
The JavaScript tag contains this parameter, which specifies the version of the Webtrends JavaScript tag that is currently deployed. The value is passed as major.minor.revision where major.minor specifies the Webtrends Analytics version and revision specifies the version of the JavaScript tag.
Although this parameter is not used in reports, it can be useful for Support when troubleshooting a tagging problem.